The invention pertains to gravel screening, sorting, mixing and conveying apparatus wherein the fines and discharge of vibrating screens may be selectively mixed and conveyed to provide the desired ratio of gravel compositions.
In the processing of pit run gravel it is the conventional practice to process the gravel through crushers, screens and conveyors to achieve the desired percentage of particle sizes in the finished product. The gravel particles are classified by vibrating screens wherein particles incapable of passing through these screens are discharged at a screen end for crushing or storing, and apparatus is available for classifying and separating various gravel sizes for intermixing with other gravel particles to achieve a desired gravel particle size composition in the finished product.
In gravel screening systems a plurality of discharge chutes are often used for classification purposes, such as shown in U.S. Pat. No. 3,425,552. Likewise, the accumulation and intermixing for proportion purposes can be achieved by a plurality of hoppers and accumulation chambers such as shown in U.S. Pat. No. 3,297,159. It is also known to use hopper guide means in conjunction with a plurality of vibrating screens to selectively direct gravel particles to the desired screen or screen box, such as shown in U.S. Pat. No. 3,388,797. However, to the applicants' knowledge, gravel screening apparatus is not available which, in a single apparatus, permits a wide variety of gravel particles to be readily screened, discharged, conveyed to a crusher, stored, proportioned and intermixed in a continuous operation whereby the proportions of gravel particle sizes may be readily varied in the finished product.
Known gravel screening apparatus is not readily available of a concise nature capable of portability wherein a high degree of flexibility of operation and choice of sequences of conveying, mixing, crushing and re-crushing is possible.